997 resultados para Theoretical constitution
Resumo:
Deterrence-based initiatives form a cornerstone of many road safety countermeasures. This approach is informed by Classical Deterrence Theory, which proposes that individuals will be deterred from committing offences if they fear the perceived consequences of the act, especially the perceived certainty, severity and swiftness of sanctions. While deterrence-based countermeasures have proven effective in reducing a range of illegal driving behaviours known to cause crashes such as speeding and drink driving, the exact level of exposure, and how the process works, remains unknown. As a result the current study involved a systematic review of the literature to identify theoretical advancements within deterrence theory that has informed evidence-based practice. Studies that reported on perceptual deterrence between 1950 and June 2015 were searched in electronic databases including PsychINFO and ScienceDirect, both within road safety and non-road safety fields. This review indicated that scientific efforts to understand deterrence processes for road safety were most intense during the 1970s and 1980s. This era produced competing theories that postulated both legal and non-legal factors can influence offending behaviours. Since this time, little theoretical progression has been made in the road safety arena, apart from Stafford and Warr's (1993) reconceptualisation of deterrence that illuminated the important issue of punishment avoidance. In contrast, the broader field of criminology has continued to advance theoretical knowledge by investigating a range of individual difference-based factors proposed to influence deterrent processes, including: moral inhibition, social bonding, self-control, tendencies to discount the future, etc. However, this scientific knowledge has not been directed towards identifying how to best utilise deterrence mechanisms to improve road safety. This paper will highlight the implications of this lack of progression and provide direction for future research.
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This study investigates friendships between gay sales associates and heterosexual female customers in luxury retail settings. By employing grounded theory methodology, the study integrates theories and findings from diverse literature streams into an original conceptual framework to illustrate the resources gay sales associates and straight female customers receive from and provide to each other during retail exchanges. The study explains why gay male–straight female friendships are uniquely suited for luxury consumption settings. Female customers characterize their friendships with gay sales associates as providing honesty, security, trust, and comfort, which stems from the absence of sexual interest and a lack of inter-female competition. Gay sales associates receive acceptance for who they are and for their displays of unconventional masculinity in retail settings. They also obtain a temporary rite from their female customers, a so-called mandate of privacy, which permits both parties to ignore the bounds of modesty and accept a degree of intimacy. Such intimacy facilitates transactions that require both personalization and customer–employee closeness, such as the selling of high-end apparel, accessories, and jewelry.
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A new dearomatized porphyrinoid, 5,10-diiminoporphodimethene (5,10-DIPD), has been prepared by palladium-catalyzed hydrazination of 5,10-dibromo-15,20-bis(3,5-di-tert-butylphenyl)porphyrin and its nickel(II) complex, by using ethyl and 4-methoxybenzyl carbazates. The oxidative dearomatization of the porphyrin ring occurs in high yield. Further oxidation with 2,3-dichloro-5,6-dicyanobenzoquinone forms the corresponding 5,10-bis(azocarboxylates), thereby restoring the porphyrin aromaticity. The UV/visible spectra of the NiII DIPDs exhibit remarkable redshifts of the lowest-energy bands to 780 nm, and differential pulse voltammetry reveals a contracted electrochemical HOMO–LUMO gap of 1.44 V. Density functional theory (DFT) was used to calculate the optimized geometries and frontier molecular orbitals of model 5,10-DIPD Ni7c and 5,10-bis(azocarboxylate) Ni8c. The conformations of the carbamate groups and the configurations of the CNZ unit were considered in conjunction with the NOESY spectra, to generate the global minimum geometry and two other structures with slightly higher energies. In the absence of solution data regarding conformations, ten possible local minimum conformations were considered for Ni8c. Partition of the porphyrin macrocycle into tri- and monopyrrole fragments in Ni7c and the inclusion of terminal conjugating functional groups generate unique frontier molecular orbital distributions and a HOMO–LUMO transition with a strong element of charge transfer from the monopyrrole ring. Time-dependent DFT calculations were performed for the three lowest-energy structures of Ni7c and Ni8c, and weighting according to their energies allowed the prediction of the electronic spectra. The calculations reproduce the lower-energy regions of the spectra and the overall forms of the spectra with high accuracy, but agreement is not as good in the Soret region below 450 nm.
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Spin-density maps, deduced from polarized neutron diffraction experiments, for both the pair and chain compounds of the system Mn2+Cu2+ have been reported recently. These results have motivated us to investigate theoretically the spin populations in such alternant mixed-spin systems. In this paper, we report our studies on the one-dimensional ferrimagnetic systems (S-A,S-B)(N) where hi is the number of AB pairs. We have considered all cases in which the spin Sri takes on allowed values in the range I to 7/2 while the spin S-B is held fixed at 1/2. The theoretical studies have been carried out on the isotropic Heisenberg model, using the density matrix renormalization group method. The effect of the magnitude of the larger spin SA On the quantum fluctuations in both A and B sublattices has been studied as a function of the system size N. We have investigated systems with both periodic and open boundary conditions, the latter with a view to understanding end-of-chain effects. The spin populations have been followed as a function of temperature as well as an applied magnetic field. High-magnetic fields are found to lead to interesting re-entrant behavior. The ratio of spin populations P-A-P-B is not sensitive to temperature at low temperatures.
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C60Br8, unlike C60Br6 and C60Cl6, forms a solid charge-transfer compound with tetrathiafulvalene (TTF), the composition being C60Br8(TTF)(8). The unique complex-forming property of C60Br8 can be understood on the basis of the electronic structures of the halogenated derivatives of C-60. Molecular orbital calculations show that the low LUMO energy of C60Br8 compared with the other halogen derivatives renders the formation of the complex with TTF favourable, the four virtual LUMOs being able to accept 8 electrons. The Raman spectrum of C60Br8(TTF)(8) shows a marked softening of the bands (-46 cm(-1) on average) with respect to C60Br8 suggesting that indeed 8 electrons are transferred per C60Br8 molecule, one from each TTF molecule. The complex is weakly paramagnetic and shows a magnetic transition around 80 K.
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Analytical techniques for measuring and planning railway capacity expansion activities have been considered in this article. A preliminary mathematical framework involving track duplication and section sub divisions is proposed for this task. In railways these features have a great effect on network performance and for this reason they have been considered. Additional motivations have also arisen from the limitations of prior models that have not included them.
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The theory for time-resolved, pump-probe, photoemission spectroscopy and other pump-probe experiments is developed. The formal development is completely general, incorporating all of the nonequilibrium effects of the pump pulse and the finite time width of the probe pulse, and including possibilities for taking into account band structure and matrix element effects, surface states, and the interaction of the photoexcited electrons with the system leading to corrections to the sudden approximation. We also illustrate the effects of windowing that arise from the finite width of the probe pulse in a simple model system by assuming the quasiequilibrium approximation.
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Quantifying the stiffness properties of soft tissues is essential for the diagnosis of many cardiovascular diseases such as atherosclerosis. In these pathologies it is widely agreed that the arterial wall stiffness is an indicator of vulnerability. The present paper focuses on the carotid artery and proposes a new inversion methodology for deriving the stiffness properties of the wall from cine-MRI (magnetic resonance imaging) data. We address this problem by setting-up a cost function defined as the distance between the modeled pixel signals and the measured ones. Minimizing this cost function yields the unknown stiffness properties of both the arterial wall and the surrounding tissues. The sensitivity of the identified properties to various sources of uncertainty is studied. Validation of the method is performed on a rubber phantom. The elastic modulus identified using the developed methodology lies within a mean error of 9.6%. It is then applied to two young healthy subjects as a proof of practical feasibility, with identified values of 625 kPa and 587 kPa for one of the carotid of each subject.
Resumo:
Background: Despite being the stiffest airway of the bronchial tree, the trachea undergoes significant deformation due to intrathoracic pressure during breathing. The mechanical properties of the trachea affect the flow in the airway and may contribute to the biological function of the lung. Method: A Fung-type strain energy density function was used to investigate the nonlinear mechanical behavior of tracheal cartilage. A bending test on pig tracheal cartilage was performed and a mathematical model for analyzing the deformation of tracheal cartilage was developed. The constants included in the strain energy density function were determined by fitting the experimental data. Result: The experimental data show that tracheal cartilage is a nonlinear material displaying higher strength in compression than in tension. When the compression forces varied from -0.02 to -0.03 N and from -0.03 to -0.04 N, the deformation ratios were 11.03±2.18% and 7.27±1.59%, respectively. Both were much smaller than the deformation ratios (20.01±4.49%) under tension forces of 0.02 to 0.01 N. The Fung-type strain energy density function can capture this nonlinear behavior very well, whilst the linear stress-strain relation cannot. It underestimates the stability of trachea by exaggerating the displacement in compression. This study may improve our understanding of the nonlinear behavior of tracheal cartilage and it may be useful for the future study on tracheal collapse behavior under physiological and pathological conditions.
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The theoretical optimization of the design parametersN A ,N D andW P has been done for efficient operation of Au-p-n Si solar cell including thermionic field emission, dependence of lifetime and mobility on impurity concentrations, dependence of absorption coefficient on wavelength, variation of barrier height and hence the optimum thickness ofp region with illumination. The optimized design parametersN D =5×1020 m−3,N A =3×1024 m−3 andW P =11.8 nm yield efficiencyη=17.1% (AM0) andη=19.6% (AM1). These are reduced to 14.9% and 17.1% respectively if the metal layer series resistance and transmittance with ZnS antireflection coating are included. A practical value ofW P =97.0 nm gives an efficiency of 12.2% (AM1).
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The probable modes of binding for methyl-α-d-sophoroside, methyl-β-d-sophoroside, laminariboise and cellobiose to concanavalin A have been determined using theoretical methods. Methyl-d-sophorosides can bind to concanavalin A in two modes, i.e. by placing their reducing as well as non-reducing sugar units in the carbohydrate specific binding site, whereas laminaribiose and cellobiose can reach the binding site only with their non-reducing glucose units. However, the probability for methyl-α-d-sophoroside to bind to concanavalin A with its reducing sugar residue as the occupant of the binding site is much higher than it is with its non-reducing sugar residue as the occupant of the sugar binding site. A few of the probable conformers of methyl-β-d-sophoroside can bind to concanavalin A with either the reducing or non-reducing glucose unit. Higher energy conformers of cellobiose or laminaribiose can reach the binding site with their non-reducing residues alone. The relative differences in the binding affinities of these disaccharides are mainly due to the differences in the availability of proper conformers which can reach the binding site and to non-covalent interactions between the sugar and the protein. This study also suggests that though the sugar binding site of concanavalin A accommodates a single sugar residue, the residue outwards from the binding site also interacts with concanavalin A, indicating the existence of extended concanavalin A carbohydrate interactions.
Resumo:
The conformational analysis of the synthetic peptide Boc-Cys-Pro-Val-Cys-NHMe has been carried out, as a model for small disulfide loops, in biologically active polypeptides. 'H NMR studies (270 MHz) establish that the Val(3) and Cys(4) NH groups are solvent shielded, while 13C studies establish an all-trans peptide backbone. Circular dichroism and Raman spectroscopy provide evidence for a right-handed twist of the disulfide bond. Analysis of the vicinal (JaB)c oupling constants for the two Cys residues establishes that XI - *60° for Cys(4), while some flexibility is suggested at Cys( 1). Conformational energy calculations, imposing intramolecular hydrogen bonding constraints, favor a P-turn (type I) structure with Pro(2)-Va1(3) as the corner residues. Theoretical and spectroscopic results are consistent with the presence of a transannular 4 - 1 hydrogen bond between Cys( 1) CO and Cys(4) NH groups, with the Val NH being sterically shielded from the solvent environment.
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Using first-principles density-functional calculations, we determine and analyze the Born effective charges Z(*) that describe the coupling between electric field and atomic displacements for ferromagnetic double-perovskite compound, La2NiMnO6. We find that th Born effective charge matrix of Ni in La2NiMnO6, has an anomalously large antisymmetric component, whose magnitude reduces substantially upon change in the magnetic ordering between Ni and Mn, showing it to be a magnetism-dependent electrostructural coupling. We use a local picture of the electronic structure obtained with Wannier functions, along with its band-by-band decomposition to determine its electronic origin.
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In this work, we theoretically examine recent pump/probe photoemission experiments on the strongly correlated charge-density-wave insulator TaS2.We describe the general nonequilibrium many-body formulation of time-resolved photoemission in the sudden approximation, and then solve the problem using dynamical mean-field theory with the numerical renormalization group and a bare density of states calculated from density functional theory including the charge-density-wave distortion of the ion cores and spin-orbit coupling. We find a number of interesting results: (i) the bare band structure actually has more dispersion in the perpendicular direction than in the two-dimensional planes; (ii) the DMFT approach can produce upper and lower Hubbard bands that resemble those in the experiment, but the upper bands will overlap in energy with other higher energy bands; (iii) the effect of the finite width of the probe pulse is minimal on the shape of the photoemission spectra; and (iv) the quasiequilibrium approximation does not fully describe the behavior in this system.
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This work offers a systematic phenomenological investigation of the constitutive significance of embodiment. It provides detailed analyses of subjectivity in relation to itself, to others, and to objective reality, and it argues that these basic structures cannot be made intelligible unless one takes into account how they are correlated with an embodied subject. The methodological and conceptual starting point of the treatise is the philosophy of Edmund Husserl. The investigation employs the phenomenological method and uses the descriptions and analyses provided by Husserl and his successors. The treatise is motivated and outlined systematically, and textual exegesis serves as a means for the systematic phenomenological investigation. The structure of the work conforms to the basic relations of subjectivity. The first part of the thesis explores the intimate relation between lived-body and selfhood, analyzes the phenomena of localization, and argues that self-awareness is necessarily and fundamentally embodied self-awareness. The second part examines the intersubjective dimensions of embodiment, investigates the corporal foundations of empathy, and unravels the bodily aspects of transcendental intersubjectivity. The third part scrutinizes the role of embodiment in the constitution of the surrounding objective reality: it focuses on the complex relationship between transcendental subjectivity and transcendental intersubjectivity, carefully examines the normative aspects of genetic and generative self-constitution, and argues eventually that what Husserl calls the paradox of subjectivity originates in a tension between primordial and intersubjective normativity. The work thus reinterprets the paradox of subjectivity in terms of a normative tension, and claims that the paradox is ultimately rooted in the structures of embodiment. In this manner, as a whole, the work discloses the constitutive significance of embodiment, and argues that transcendental subjectivity must be fundamentally embodied.